Deckle-strap.



No. 669,252.- Patented Mar. 5, I90I. J. B. FORSYTH.

DECKLE STRAP.

(Ayplicatiqn filed Dec. 13, 1900.

(No mm.)

ruz'uomus PETERS co Pumau u UNITED STATES JAMES BENNETT FORSYTH, OFBOSTON, MASSACHUSETTS.

DEOKLE-STRAP.

SPECIFICATION forming part of Letters Patent No. 669,252, dated March 5,1901. Application filed December 13, 1900. Serial No. 39.647. (N0model.)

To all whom it may cmwern:

Be it known that I, JAMES BENNETT FOR- sYTH, of Boston,in the county ofSuffolk and State of Massachusetts, have invented an ImprovedDeckleStrap, of which the following is a specification, reference beinghad to the accompanying drawings, in which Figure 1 is a perspectiveview illustrating a port-ion of a deckle-strap as now commonly made, andFig. 1 is an enlarged cross-section of suchadeckle-strap. Fig. 2 is asimilar perspective view illustrating a portion of myimproveddeckle-strap, and Fig. 2 is an enlarged cross-section thereof. Fig. 2 isan enlarged cross-section of a modified form.

Deckle-straps are endless straps rectangular in cross-section, which aresupported on antifriction wheels or pulleys along each side of the wireapron of a paper-making machine, the deckle-strap on one side formingone side of a trough and the deckle-strap on the other side forming theother side of that trough, the bottom of which is the wire apron, thiswire apron and the two deckle-straps traveling together several feet asecond. These deckle-straps were formerly made of strips of canvas sewedtogether to form an endless strap of proper size and shape incross-section, but have been long made by covering such a canvas strapwith rubber, as shown in Figs. 1 and l. The canvas strips making thecore (1 are in practice usually cut bias and united by a thin coating ofrubber, and their purpose is to give the proper tensile strength to thecompleted deckle-strap and yet not make it so stiff that it cannot bereadily carried around the two end wheels D, Fig. 3. Deckle-straps asheretofore made (shown in Figs. 1 and 1) should be used with the stripsof canvas d flatwise over the pulleys D, and in practice when one of thefaces of the deckle-straps becomes uneven through wear the strap isturned to bring the uneven face innermost and the opposite faceoutermost, so that the un worn face will run in contact with the wireapron; but when decklestraps of the kind shown in Figs. 1 and 1 are wornon two opposite faces the attempt to utilize the third or fourth facenot only made the strap so stiff as to be objectionable, but alsoincreased the strain and caused the rubber to crack after comparativelyshort usage, because of the canvas strips dstanding edgewise to thepulleys. This has for many years been recognized as an objection to thedecklestraps shown in Figs. 1 and 1*, and the object of my invention isto do away with that objection and to permit the use in turn of each oneof the four sides with equal advantage next to the wire apron, therebypractically doubling the life of a pair of decklestraps and also makingit impossible to apply the deckle-straps with the wrong face next theWire apron, which has heretofore accidentally occurred to the injury ofthe decklestraps for the reasons above stated. In my improveddeckle-straps the canvas core 01 is made of a sheet of canvas coatedwith rubber or the like and rolled up to form a core, the essentialmatter being to make the decklestrap equally flexible whichever one ofits four faces be used next the wire apron. Preferably I make the core01' of canvas cut bias and roll it either on itself or on a small cordof rubber compound, as it is easier to roll it by starting it on acord-like strip of compound. The core may of course be made hollow, asshown in Fig. 2 and the cores d and d may be braided-that is, mayconsist of several concentric fibrous tubes. In making the hollow core61 of canvas cut bias it is more convenient to use a mandrel coveredwith a tube of rubber d that is, one edge of the rubber-coated canvasstrip forming core (1 is first pressed upon the rubber tube on themandrel, when the canvas strip can be readily and quickly rolled up onthe mandrel.

I have shown the deckle-straps square; but they are frequently made withtwo opposite sides slightly different in width from the other twoopposite sides.

What I claim as my invention is The im proved deckle-strap abovedescribed consisting of an endless strap of rubber rectangular incross-section provided with a core of fibrous material of the sameflexibility when bent in any direction, substantially as and for thepurposes specified.

JAMES BENNETT FORSYTH.

Witnesses J. E. MAYNADIER, G. A. ROCKWELL.

